Role of tissue porosity in thermal damage during microwave ablation

Abstract

Microwave ablation (MWA) uses electromagnetic waves to produce localized heat for tumor therapy. This research examined the influence of tissue porosity on heat transmission and thermal damage patterns during microwave ablation via numerical simulations grounded in Maxwell's equations and porous media theory. Tissue necrosis was forecasted via an Arrhenius model, dependent on temperature and exposure time. The study findings show that higher tissue porosity leads to a more diffused and elongated necrotic zone due to enhanced convective heat transfer. The heightened porosity elevates fluid velocity and enhances natural convection currents, leading to a more comprehensive heat dispersion throughout the tissue, hence complicating the regulation of the tissue ablation zone and heightening the danger of harming healthy tissues. Moreover, higher microwave power levels intensify tissue heating and convection; when combined with intrinsic tissue porosity, this broadens heat dispersion and can distort the ablation-zone geometry. These observations underscore the necessity of accounting for tissue porosity in the optimization of MWA regimens. By customizing the microwave power level and exposure time to the porous nature of tissues, clinicians can predict thermal outcomes more accurately and improve tumor targeting while minimizing harm to the surrounding tissues. This approach is promising in realizing more precise and safer MWA treatments for cancer.